1. Field of the Invention
The present invention relates to a three-point set belt device for automobiles, and in particular, relates to a seat belt device including a thigh belt.
Priority is claimed on Japanese Patent Application No. 2002-297221, filed Oct. 10, 2002, the content of which is incorporated herein by reference.
2. Description of Related Art
Among seat belt devices for automobiles, a so-called three-point seat belt device (a lap and diagonal seat belt device) is known, which includes a shoulder belt (a diagonal belt) and a lap belt. A three-point seat belt device restrains the front portion of an upper half of the body of a passenger seated in the seat by the shoulder belt thereof, and restrains the front portion of the pelvis of the passenger by the lap belt thereof, so that the passenger is firmly restrained. Another seat belt device has been proposed, which improves the afore-mentioned seat belt device in such a manner that the abdomen of the passenger is not compressed even when a pregnant woman or a person having a disease in the abdomen is seated in the seat (see, for example, Japanese Unexamined Utility Model Application, First Publication No. Hei 06-44655).
This improved seat belt device will be further explained below with reference to FIG. 6. A seat belt 2, which is upwardly drawn from a retractor 1, is led through a through anchor 3. The end of the seat belt 2 is fixed to a body member 5, which is disposed at a position within the cabin closer to the outer side of the automobile cabin than a seat 4 (hereinafter referred to as an outer position with respect to the seat), using an outer anchor 6. Two self-guiding tongue plates 7 and 8 are attached to the middle portions of the seat belt 2. One of the self-guiding tongue plates, i.e., the self-guiding tongue plate 7 is engaged in a removable manner with a buckle 10 which is fixed to a body member 9 that is disposed at a position closer to the center of the automobile cabin than the seat 4 (hereinafter referred to as an inner position with respect to the seat), and the other of the self-guiding tongue plates, i.e., the self-guiding tongue plate 8 is engaged in a removable manner with another buckle 12 which is fixed to a seat frame 11 at a position in front of the seat 4. Accordingly, the portion of the seat belt 2 positioned between the self-guiding tongue plate 7 and the through anchor 3 acts as a shoulder belt 13, and another portion of the seat belt 2 positioned between the self-guiding tongue plate 7 and the outer anchor 6 acts as a lap belt 14 which restrains the thighs of the passenger.
In the above seat belt device, because the middle portion of the lap belt 14 is supported by the seat frame 11 at a position in front of the seat 4, the compressive force applied to the abdomen of the passenger is reduced, which is a superior property; however, the front portion of the pelvis of the passenger, which tends to move forward, still must be supported by the lap belt 14; therefore, the load applied to the passenger is not greatly reduced.
Moreover, when the passenger is a woman wearing a skirt, the woman tends to hesitate to fix the self-guiding tongue plate 8, which is another problem.